Technical Field
The present invention is broadly concerned with polypropylene polymer composites comprising asphaltenes.
Description of the Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
Polypropylene (PP) is one of the fastest growing polymers among thermoplastics. This growth is ascribed to its appealing combination of low cost, good processability, low weight and tunable properties. These properties resulted in PP being employed in a wide variety of applications such as the automotive industry for interior trims, instrument panels, food packaging, stationery, plastic parts, textiles and others. It can be also formed into fibers, which have low absorbance and high strain resistance, for clothing and home furnishing, especially carpeting. Polypropylene is a polymorphic material with several possible modifications: the monoclinic (α-modification), the trigonal (β-modification) and the orthorhombic (γ-modification) (A. T. Jones, J. M. Aizlewood, D. R. Beckett. Crystalline forms of isotactic polypropylene. Makromol. Chem. 75 (1964) 134-158, incorporated herein by reference in its entirety). The α-form of PP is the most stable thermodynamically and for this reason, the majority of the commercial grades of PP crystallize essentially in the monoclinic system. In order to improve the properties of PP to match the profile of a typical engineering thermoplastic, proper fillers or reinforcements are incorporated into the PP matrix (J. Karger-Kocsis, Ed. Polypropylene structure, blends and composites-Composites; Chapman & Hall: London, 1995; Vol. 3, incorporated herein by reference in its entirety). Thus, composites of PP with a number of fillers have been prepared and studied in literature (G. Tartaglione, D. Tabuani, G. Camino, M. Moisio. PP and PBT composites filled with sepiolite: Morphology and thermal behaviour. Compos. Sci. Technol. 68 (2008) 451-460; P. Peng, Z. Yang, M. Wu, Q. Zhang, G. Chen. Effect of montmorillonite modification and maleic anhydride-grafted PP on the microstructure and mechanical properties of PP/MMT nanocomposites. J. Appl. Polym. Sci. 130 (2013) 3952-3960; J. H. Joo, J. H. Shim, J. H. Choi, C.-H. Choi, D.-S. Kim, J.-S. Yoon. The effect of the silane modification of an organoclay on the properties of polypropylene/clay composites. J. Appl. Polym. Sci. 109 (2008) 3645-3650; N. A. Rahman, A. Hassan, R. Yahya, R. A. Lafia-Araga, P. Hornsby. Micro-structural, thermal and mechanical properties of injection-molded glass fiber/nanoclay/polypropylene composites. J. Rein. Plast. Compos. 31 (2012) 269-281; H. Lee, D. S. Kim Preparation and physical properties of wood/polypropylene/clay nanocomposites. J. Appl. Polym. Sci. 111 (2009) 2769-2776; Z. T. Yao, T. Chen, H. Y. Li, M. S. Xia, Y. Ye, H. Zheng. Mechanical and thermal properties of polypropylene composites filled with modified shell waste. J. Hazard. Mater. 262 (2013) 212-217; Z. Lin, Z. Guan, C. Chen, L. Cao, Y. Wang, S. Gao, B. Xu, W. Li. Preparation, structures and properties of shell/polypropylene biocomposites. Thermochim. Acta 551 (2013) 149-154, each incorporated herein by reference in their entirety).
Tartaglione et al. studied the morphology and thermal behavior of PP composites filled with pristine or organomodified sepiolite (G. Tartaglione, D. Tabuani, G. Camino, M. Moisio. PP and PBT composites filled with sepiolite: Morphology and thermal behaviour. Compos. Sci. Technol. 68 (2008) 451-460, incorporated herein by reference in its entirety). The effect of montmorillonite (MMT) modification and maleic anhydride-grafted PP on the microstructure and mechanical properties of PP/MMT nanocomposites was investigated by Peng et al. (P. Peng, Z. Yang, M. Wu, Q. Zhang, G. Chen. Effect of montmorillonite modification and maleic anhydride-grafted PP on the microstructure and mechanical properties of PP/MMT nanocomposites. J. Appl. Polym. Sci. 130 (2013) 3952-3960—incorporated herein by reference in its entirety). It was found that the highly dispersed MMT in PP matrix increased the number of spherulite crystals, enhanced the melting enthalpy and improved the thermal stability. The effect of the silane modification of an organoclay on the properties of polypropylene/clay composites was further investigated by Joo et al. (J. H. Joo, J. H. Shim, J. H. Choi, C.-H. Choi, D.-S. Kim, J.-S. Yoon. The effect of the silane modification of an organoclay on the properties of polypropylene/clay composites. J. Appl. Polym. Sci. 109 (2008) 3645-3650—incorporated herein by reference in its entirety). These composites were found to possess good tensile properties. Hybrid composites of PP with glass fiber and nanoclay were prepared by Rahman et al., and their microstructural, thermal and mechanical properties were studied (N. A. Rahman, A. Hassan, R. Yahya, R. A. Lafia-Araga, P. Hornsby. Micro-structural, thermal and mechanical properties of injection-molded glass fiber/nanoclay/polypropylene composites. J. Rein. Plast. Compos. 31 (2012) 269-281, incorporated herein by reference in its entirety). It was found that the thermal stability of the material improved, as well as the flexural strength and the modulus of the material.
Nanocomposites of PP with wood and an organomodified clay were prepared by Lee and Kim (H. Lee, D. S. Kim Preparation and physical properties of wood/polypropylene/clay nanocomposites. J. Appl. Polym. Sci. 111 (2009) 2769-2776, incorporated herein by reference in its entirety). The performance of the wood/PP composites was improved by the incorporation of the nanoclay.
Calcium carbonate is the most widely used inorganic filler in polymers. Yao et al. used it to form PP composites (Z. T. Yao, T. Chen, H. Y. Li, M. S. Xia, Y. Ye, H. Zheng. Mechanical and thermal properties of polypropylene composites filled with modified shell waste. J. Hazard. Mater. 262 (2013) 212-217, incorporated herein by reference in its entirety). The mechanical properties and the thermal stability of the materials formed were significantly improved compared to pristine PP, and the maximum amount of the filler was found to be around 15%. Biocomposites of shells with PP were also prepared by Lin et al. and results showed that modified shells were n-nucleating agents in the crystallization of PP (Lin, Z. Guan, C. Chen, L. Cao, Y. Wang, S. Gao, B. Xu, W. Li. Preparation, structures and properties of shell/polypropylene biocomposites. Thermochim. Acta 551 (2013) 149-154, incorporated herein by reference in its entirety).
In the petroleum refining industry, pyrolysis and/or hydrocracking processes convert heavy petroleum oils and high-boiling residues to more valuable lower-boiling products, such as gasoline and diesel oil. The feedstock contains a significant amount of asphaltenes, which are high molecular weight, polycondensed aromatic compounds bearing long aliphatic hydrocarbon chains. Heavy crude oils contain higher proportions of asphaltenes than do medium or light oils. Asphaltenes contain mainly carbon and hydrogen atoms in the form of highly complex structures that is not known accurately yet (M. N. Siddiqui, Alkylation and Oxidation Reactions of Arabian Asphaltenes, Fuel, 82(11) (2003) 1323-1329, incorporated herein by reference in its entirety).
In view of the foregoing, the objective of the present disclosure is to provide a polymer composite comprising asphaltenes. It is a further objective to present an application of a by-product of the petroleum refining industry in manufacturing polymer composites with enhanced thermal and mechanical properties.